/* Adds a triangle by interpolating over the given edges (which are expected to
* contain an intersection).
* The edges are specified by their vertices (u is the first edge, v the second,
* etc.)
*/
void interpolate_edges(triangle *triangles, unsigned char isovalue, cell c,
int u0, int u1,
int v0, int v1,
int w0, int w1)
{
vec3 p1, p2, p3;
p1 = interpolate_points(isovalue, c.p[u0], c.p[u1], c.value[u0], c.value[u1]);
p2 = interpolate_points(isovalue, c.p[v0], c.p[v1], c.value[v0], c.value[v1]);
p3 = interpolate_points(isovalue, c.p[w0], c.p[w1], c.value[w0], c.value[w1]);
triangles->p[0] = p1;
triangles->p[1] = p2;
triangles->p[2] = p3;
// the surface-normal is the cross-product between 2 of the edges making up
// the face
vec3 normal = v3_crossprod(v3_subtract(p1, p2),
v3_subtract(p3, p1));
normal = v3_normalize(normal);
normal = v3_multiply(normal, -1);
triangles->n[0] = normal;
triangles->n[1] = normal;
triangles->n[2] = normal;
}
int
stp_curve_compose(stp_curve_t **retval,
stp_curve_t *a, stp_curve_t *b,
stp_curve_compose_t mode, int points)
{
stp_curve_t *ret;
double *tmp_data;
double gamma_a = stp_curve_get_gamma(a);
double gamma_b = stp_curve_get_gamma(b);
unsigned points_a = stp_curve_count_points(a);
unsigned points_b = stp_curve_count_points(b);
double alo, ahi, blo, bhi;
if (a->piecewise && b->piecewise)
return 0;
if (a->piecewise)
{
stp_curve_t *a_save = a;
a = stp_curve_create_copy(a_save);
stp_curve_resample(a, stp_curve_count_points(b));
}
if (b->piecewise)
{
stp_curve_t *b_save = b;
b = stp_curve_create_copy(b_save);
stp_curve_resample(b, stp_curve_count_points(a));
}
if (mode != STP_CURVE_COMPOSE_ADD && mode != STP_CURVE_COMPOSE_MULTIPLY)
return 0;
if (stp_curve_get_wrap(a) != stp_curve_get_wrap(b))
return 0;
stp_curve_get_bounds(a, &alo, &ahi);
stp_curve_get_bounds(b, &blo, &bhi);
if (mode == STP_CURVE_COMPOSE_MULTIPLY && (alo < 0 || blo < 0))
return 0;
if (stp_curve_get_wrap(a) == STP_CURVE_WRAP_AROUND)
{
points_a++;
points_b++;
}
if (points == -1)
{
points = lcm(points_a, points_b);
if (stp_curve_get_wrap(a) == STP_CURVE_WRAP_AROUND)
points--;
}
if (points < 2 || points > curve_point_limit ||
((stp_curve_get_wrap(a) == STP_CURVE_WRAP_AROUND) &&
points > curve_point_limit - 1))
return 0;
if (gamma_a && gamma_b && gamma_a * gamma_b > 0 &&
mode == STP_CURVE_COMPOSE_MULTIPLY)
return create_gamma_curve(retval, alo * blo, ahi * bhi, gamma_a + gamma_b,
points);
tmp_data = stp_malloc(sizeof(double) * points);
if (!interpolate_points(a, b, mode, points, tmp_data))
{
stp_free(tmp_data);
return 0;
}
ret = stp_curve_create(stp_curve_get_wrap(a));
if (mode == STP_CURVE_COMPOSE_ADD)
{
stp_curve_rescale(ret, (ahi - alo) + (bhi - blo),
STP_CURVE_COMPOSE_MULTIPLY, STP_CURVE_BOUNDS_RESCALE);
stp_curve_rescale(ret, alo + blo,
STP_CURVE_COMPOSE_ADD, STP_CURVE_BOUNDS_RESCALE);
}
else
{
stp_curve_rescale(ret, (ahi - alo) * (bhi - blo),
STP_CURVE_COMPOSE_MULTIPLY, STP_CURVE_BOUNDS_RESCALE);
stp_curve_rescale(ret, alo * blo,
STP_CURVE_COMPOSE_ADD, STP_CURVE_BOUNDS_RESCALE);
}
if (! stp_curve_set_data(ret, points, tmp_data))
goto bad1;
*retval = ret;
stp_free(tmp_data);
return 1;
bad1:
stp_curve_destroy(ret);
stp_free(tmp_data);
return 0;
}
static int
generate_tetrahedron_triangles(triangle *triangles, unsigned char isovalue, cell c, int v0, int v1, int v2, int v3)
{
int w1 = 0, w2 = 0, w3 = 0, w0 = 0;
if(volume[(int)c.value[v0]] > isovalue)
w0 = 1;
if(volume[(int)c.value[v1]] > isovalue)
w1 = 1;
if(volume[(int)c.value[v2]] > isovalue)
w2 = 1;
if(volume[(int)c.value[v3]] > isovalue)
w3 = 1;
/* interpolate as shown in figure 10 of assignment. */
if((w3 == 0 && w2 == 0 && w1 == 0 && w0 == 1) || (w3 == 1 && w2 == 1 && w1 == 1 && w0 == 0))
{
triangles[0].p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], c.value[v0], c.value[v1]);
triangles[0].p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], c.value[v0], c.value[v2]);
triangles[0].p[2] = interpolate_points(isovalue, c.p[v0], c.p[v3], c.value[v0], c.value[v3]);
return 1;
}
if((w3 == 0 && w2 == 0 && w1 == 1 && w0 == 0) || (w3 == 1 && w2 == 1 && w1 == 0 && w0 == 1))
{
triangles[0].p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], c.value[v0], c.value[v1]);
triangles[0].p[1] = interpolate_points(isovalue, c.p[v1], c.p[v2], c.value[v1], c.value[v2]);
triangles[0].p[2] = interpolate_points(isovalue, c.p[v1], c.p[v3], c.value[v1], c.value[v3]);
return 1;
}
if((w3 == 0 && w2 == 1 && w1 == 0 && w0 == 0) || (w3 == 1 && w2 == 0 && w1 == 1 && w0 == 1))
{
triangles[0].p[0] = interpolate_points(isovalue, c.p[v2], c.p[v0], c.value[v2], c.value[v0]);
triangles[0].p[1] = interpolate_points(isovalue, c.p[v1], c.p[v2], c.value[v1], c.value[v2]);
triangles[0].p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], c.value[v2], c.value[v3]);
return 1;
}
if((w3 == 1 && w2 == 0 && w1 == 0 && w0 == 0) || (w3 == 0 && w2 == 1 && w1 == 1 && w0 == 1))
{
triangles[0].p[0] = interpolate_points(isovalue, c.p[v3], c.p[v0], c.value[v3], c.value[v0]);
triangles[0].p[1] = interpolate_points(isovalue, c.p[v1], c.p[v3], c.value[v1], c.value[v3]);
triangles[0].p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], c.value[v2], c.value[v3]);
return 1;
}
if((w3 == 0 && w2 == 0 && w1 == 1 && w0 == 1) || (w3 == 1 && w2 == 1 && w1 == 0 && w0 == 0))
{
triangles[0].p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], c.value[v0], c.value[v1]);
triangles[0].p[1] = interpolate_points(isovalue, c.p[v1], c.p[v2], c.value[v1], c.value[v2]);
triangles[0].p[2] = interpolate_points(isovalue, c.p[v1], c.p[v3], c.value[v1], c.value[v3]);
triangles[1].p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], c.value[v0], c.value[v1]);
triangles[1].p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], c.value[v0], c.value[v2]);
triangles[1].p[2] = interpolate_points(isovalue, c.p[v0], c.p[v3], c.value[v0], c.value[v3]);
return 2;
}
if((w3 == 0 && w2 == 1 && w1 == 0 && w0 == 1) || (w3 == 1 && w2 == 0 && w1 == 1 && w0 == 0))
{
triangles[0].p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], c.value[v0], c.value[v1]);
triangles[0].p[1] = interpolate_points(isovalue, c.p[v0], c.p[v2], c.value[v0], c.value[v2]);
triangles[0].p[2] = interpolate_points(isovalue, c.p[v0], c.p[v3], c.value[v0], c.value[v3]);
triangles[1].p[0] = interpolate_points(isovalue, c.p[v2], c.p[v0], c.value[v2], c.value[v0]);
triangles[1].p[1] = interpolate_points(isovalue, c.p[v1], c.p[v2], c.value[v1], c.value[v2]);
triangles[1].p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], c.value[v2], c.value[v3]);
return 2;
}
if((w3 == 0 && w2 == 1 && w1 == 1 && w0 == 0) || (w3 == 1 && w2 == 0 && w1 == 0 && w0 == 1))
{
triangles[0].p[0] = interpolate_points(isovalue, c.p[v2], c.p[v0], c.value[v2], c.value[v0]);
triangles[0].p[1] = interpolate_points(isovalue, c.p[v1], c.p[v2], c.value[v1], c.value[v2]);
triangles[0].p[2] = interpolate_points(isovalue, c.p[v2], c.p[v3], c.value[v2], c.value[v3]);
triangles[1].p[0] = interpolate_points(isovalue, c.p[v0], c.p[v1], c.value[v0], c.value[v1]);
triangles[1].p[1] = interpolate_points(isovalue, c.p[v1], c.p[v2], c.value[v1], c.value[v2]);
triangles[1].p[2] = interpolate_points(isovalue, c.p[v1], c.p[v3], c.value[v1], c.value[v3]);
return 2;
}
return 0;
}
